romeomanzur I have not been able to find a way to get a socket.io app to work correctly when the app's node server is running via a sub-URL like /chat.
To work around this you can run the Node app on a separate site on a different subdomain, and then serve /chat/ from a subdirectory of your "mvp_production" app. For example:
Add a new subdomain like chat.mvpfantasysports.com at https://my.opalstack.com/domains/.
Create a new site to serve your "mvp_chat" app on the new subdomain.
Create a new subdirectory /home/mvp/apps/mvp_production/chat on your server.
Copy index.html from /home/mvp/apps/mvp_chat/ into /home/mvp/apps/mvp_production/chat/.
Edit the copy of index.html to change the URLs for socket.io:
<script src="http://chat.mvpfantasysports.com/socket.io/socket.io.js"></script>
and
var socket = io('http://chat.mvpfantasysports.com/');
When this is done the chat server will be running on the root of the chat.mvpfantasysports.com subdomain and will accept requests from mvpfantasysports.com.